Electromagnetic-shielding light-diffusing sheet

Abstract

A subject for the invention is to provide an electromagnetic-shielding light-diffusing sheet which has satisfactory electromagnetic shielding performance, attains a large transmitted-light amount, and can emit even diffused light having reduced unevenness of luminance. The invention relates to an electromagnetic-shielding light-diffusing sheet comprising a light-diffusing sheet main body and, laminated on at least one side thereof, a light-transmitting electroconductive layer having a surface resistivity of 10 5 Ω/□ or lower.

1 . An electromagnetic-shielding light-diffusing sheet, which comprises a light-diffusing sheet main body and, laminated on at least one side thereof, a light-transmitting electroconductive layer having a surface resistivity of 10 5  Ω/□ or lower.  
   
   
       2 . The electromagnetic-shielding light-diffusing sheet according to  claim 1 , wherein the light-diffusing sheet main body contains a light-diffusing agent.  
   
   
       3 . The electromagnetic-shielding light-diffusing sheet according to  claim 2 , wherein the light-diffusing agent is contained in an amount of 0.1-35% by mass.  
   
   
       4 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  3 , wherein the light-diffusing sheet has fine recesses and protrusions formed on at least one side thereof.  
   
   
       5 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  4 , wherein the light-diffusing sheet main body is a multilayered sheet comprising at least a core layer and a surface layer, and wherein the core layer contains a light-diffusing agent and the surface layer contains no light-diffusing agent.  
   
   
       6 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  4 , wherein the light-diffusing sheet main body is a multilayered sheet comprising at least a core layer and a surface layer, and wherein the core layer contains no light-diffusing agent and the surface layer contains a light-diffusing agent.  
   
   
       7 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  4 , wherein the light-diffusing sheet main body is a multilayered sheet comprising at least a core layer and a surface layer, and wherein the core layer and the surface layer contain a light-diffusing agent.  
   
   
       8 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 5  to  7 , wherein the light-diffusing sheet main body is a multilayered sheet comprising at least a core layer and a surface layer, and wherein the light-transmitting resin used for the surface layer is a resin having a lower refractive index than the light-transmitting resin used for the core layer.  
   
   
       9 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 5  to  8 , wherein at least the surface layer contains an ultraviolet absorber.  
   
   
       10 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  9 , wherein the light-diffusing sheet main body is made of a light-transmitting polypropylene resin containing a talc light-diffusing agent in an amount of 15-35% by mass and the light-diffusing sheet has fine recesses and protrusions formed on each side thereof.  
   
   
       11 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 5  to  9 , wherein the light-diffusing sheet main body is a multilayered sheet comprising a core layer made of a light-transmitting polypropylene resin containing a talc light-diffusing agent in an amount of 15-35% by mass and, laminated on at least one side of the core layer, a surface layer made of a light-transmitting resin, and wherein the light-diffusing sheet has fine recesses and protrusions formed on each side thereof.  
   
   
       12 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 5  to  9 , wherein the light-diffusing sheet main body is a multilayered sheet comprising a core layer made of a light-transmitting polycarbonate resin containing an acrylic light-diffusing agent in an amount of 0.1-20% by mass and, laminated on at least one side of the core layer, a surface layer made of a light-transmitting resin.  
   
   
       13 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  12 , wherein the light-transmitting electroconductive layer is a metal oxide layer.  
   
   
       14 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  12 , wherein the light-transmitting electroconductive layer is a layer containing ultrafine electroconductive fibers.  
   
   
       15 . The electromagnetic-shielding light-diffusing sheet according to  claim 14 , wherein the ultrafine electroconductive fibers are in a dispersed state without aggregating and are in contact with one another.  
   
   
       16 . The electromagnetic-shielding light-diffusing sheet according to  claim 14  or  15 , wherein the ultrafine electroconductive fibers are in contact with one another in such a state that the individual fibers have been dispersed separately from one another or that individual bundles composed of plural ultrafine electroconductive fibers have been dispersed separately from one another.  
   
   
       17 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 14  to  16 , wherein the ultrafine electroconductive fibers are carbon nanotubes.  
   
   
       18 . The electromagnetic-shielding light-diffusing sheet according to  claim 17 , wherein the estimated content of the carbon nanotubes contained in the light-transmitting electroconductive layer is 20-450 mg/m 2  and the light-transmitting electroconductive layer has a thickness of 10-400 nm.  
   
   
       19 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  18 , wherein the electromagnetic-shielding light-diffusing sheet has a total light transmittance of 50-95% and a haze of 30-95%.  
   
   
       20 . The electromagnetic-shielding light-diffusing sheet according to any one of  claims 1  to  19 , which has a light-transmitting resin cover layer laminated on the light-transmitting electroconductive layer.